The Idaho Transportation Department invites community members to view design plans for a new bridge over the North Fork Payette River at a public meeting on July 22 in Cascade. The new bridge will replace the existing Rainbow Bridge on State Highway 55.
Community members may stop by the meeting at their convenience between 4 and 7 p.m. at the American Legion Post 60 (105 Mill St.) in Cascade. Project staff will be on hand to answer questions. Those who cannot attend in person are invited to participate online at sh55rainbowbridge.com anytime between July 22 and Aug. 5.
The open house will include an update on the project, design options for the new bridge and retaining walls, and an update about the existing Rainbow Bridge.
“Community input will play an important role in the selection of a new bridge design,” District Engineer Jason Brinkman said. “Since our last public meeting in summer 2024, we have completed extensive technical work for the new bridge design and have thoroughly evaluated the condition of the existing bridge. We look forward to sharing the outcomes and gathering input.”
The existing Rainbow Bridge was constructed in 1933 and no longer meets standards for state highway bridges. The new bridge will be located slightly northwest and upstream of the current location. It will include wider lanes and shoulders, and improved sight distance for traffic crossing the bridge.
In addition to the community open house, ITD will meet with a Bridge Involvement Group on July 9. The group includes community leaders, stakeholders and others who have agreed to invest additional time in the project. A recording of the meeting will be posted to the project website.
Construction of the new bridge is programmed to begin in 2028.
Motorists can expect lane restrictions on State Highway 55 between the Idaho Oregon Nevada (ION) Junction and Hoskins Road beginning Monday (July 14). The Idaho Transportation Department will apply a protective sealcoat to seven miles of the highway surface to preserve and extend the life of the roadway.
Construction will begin at the ION Junction near Marsing and move towards Hoskins Road in Caldwell. All work is expected to be completed by mid-August.
Motorists can expect:
- SH-55 will be reduced to one lane with flaggers when crews are on site. All lanes will be open outside of working hours.
- All work will take place during daytime hours from 7 a.m. to 7 p.m.
- Speed limits will be reduced to 35 mph in the work zone.
- 12-foot width restrictions will be in place.
Community members can request email updates about this project by visiting lp.constantcontactpages.com/sv/pI5SwgY. Questions may be directed to (208) 402-8408 or info@itdsealcoats.org.
For real-time traffic impacts, drivers are encouraged to use the Idaho 511 system to plan ahead for travel.
The Idaho Transportation Department will apply a sealcoat on State Highway 55 from Horseshoe Bend to north of Banks this summer. The sealcoat will preserve and extend the life of the pavement.
Starting Wednesday crews will begin work at the boundary of the Boise National Forest at milepost 91, about 12 miles north of Banks, and work their way 28 miles south towards Horseshoe Bend. This work is expected to be completed in early August.
During construction, motorists can expect:
- SH-55 will be reduced to one lane with flaggers and pilot cars inside the active work zone.
- The speed limit will be reduced and 12-foot width restrictions may be in place.
- Work will take place Monday through Thursday from 6 a.m. to 9 p.m. and Friday from 6 a.m. to 12 p.m.
- All lanes will be open on the weekends and outside working hours.
Due to the popularity of this highway with recreationists, drivers should plan for delays up to 30 minutes and consider using an alternative route.
There are several other work zones active on this highway. Workers will be close to traffic. Slow down and do not block driveways and entrances along SH-55.
Visit the project website at itdprojects.idaho.gov/pages/55sealcoat to learn more, sign up for email updates or contact the project team.
For real-time traffic impacts drivers are encouraged to use the Idaho 511 system to plan ahead for travel.
Earlier this week the contractor for the Idaho Transportation Department resumed construction to replace the Little Goose Creek Bridge along State Highway 55 between New Meadows and McCall.
Drivers should plan for reduced speeds and intermittent flagging for most of construction. Later this summer during paving, SH-55 will be reduced to one lane with temporary traffic signals.
“This project has been extended due to weather, road conditions and unexpected contractor delays,” Associate Engineer B.J. Johnson said. “We are working with the contractor to ensure the work is completed as quickly and safely as possible, presumably this fall. We appreciate the community’s patience during this process.”
Work began in June 2024 to replace the bridge to enhance the overall safety, mobility and needs of the traveling public. The project also includes improving the nearby intersection at Last Chance Road and widening the shoulders of the highway. Last Chance Road and campground are closed until late 2025.
Learn more and sign up for construction updates on the project website at itdprojects.idaho.gov/pages/55-little-goose-creek.
CANYON COUNTY – The Idaho Transportation Department will begin maintenance work on two bridges in Canyon County starting Sunday night. Crews will work on both bridges simultaneously with construction lasting approximately one week.
The structures being repaired include the bridge for the eastbound on-ramp that crosses Indian Creek at the Karcher Interchange in Nampa and the Centennial Way Railroad bridge in Caldwell. Work will take place between 8 p.m. and 5 a.m. with speed limits reduced to 35 mph.
At the Karcher Interchange, the on-ramp will be closed. Motorists will still be able to access I-84 by following the signed detour.
At the Centennial Way Railroad Bridge, one lane will be open in each direction.
This work is part of a larger effort to repair bridges throughout southwestern Idaho to extend their service life and reduce maintenance costs. ITD has completed work on bridges in Elmore and Ada counties and will be working on bridges along US-95 in Adams/Idaho counties later this summer.
Repairs will include:
- Patching and sealing concrete
- Working on expansion joints
- Removing asphalt overlays
- Improving deck drains
- Milling and paving bridge approaches
- Painting steel structures
ITD is committed to minimizing disruption during construction while prioritizing the safety of both crews and motorists. Drivers are urged to use extra caution when traveling through active work zones.
To learn more about the project or sign up for construction updates visit the project website at ITDProjects.Idaho.Gov/pages/Bridges2025
NAMPA – Motorists can expect lane restrictions on State Highway 45 between Deer Flat Road and Junction 78 near Walter’s Ferry while the Idaho Transportation Department applies a protective sealcoat to the roadway. The project will extend the life of the asphalt.
Starting Monday, crews will remove pavement markings, and flaggers will be in place to direct traffic.
Crews will begin work at Deer Flat Road in south Nampa and work their way 12 miles south toward Junction 78. Work is expected to be completed by late July.
Motorists can expect that:
- SH-45 will be reduced to one lane in the work zone. Flaggers and pilot cars will direct traffic.
- Work will take place from 7:30 a.m. to 7:30 p.m. Monday through Sunday. All lanes will be open outside of working hours.
- Speed limits will be reduced, and 12-foot lane restrictions may be in place.
Questions may be directed to (208) 402-8408 or info@itdsealcoats.org.
Current restrictions are also posted to 511.idaho.gov.
Since Transportation Expansion and Congestion Mitigation funds were first used by the department for bonding and advancing major projects in 2022, ITD has delivered timely construction of expansion projects across the state. Today’s actions are a continuation of that.
Funding came from House Bill 25, which was passed by the Idaho Legislature earlier this year. The legislation provides an additional $20 million a year to the TECM fund for the next three years and allows the department to invest an extra $1 billion in the Idaho transportation system.
With this new funding, the following projects have been recommended for further design and construction:
- SH-16 from SH-44 to Beacon Light: This project will increase capacity by widening the road from two to four lanes with a median barrier between the future SH-44 Interchange and Beacon Light Road. An overpass will be added at Floating Feather Road. Construction is anticipated to start in 2027, one year earlier than planned.
- I-84 Mobility Improvements: The ongoing study will provide a prioritized list of operational improvements like auxiliary lanes between Boise and Nampa, and this revenue stream will provide construction funding for the highest priority needs that emerge from the study.
- US-20/26 from Middleton to Star: This project will add capacity by widening the road to two lanes in both directions and improve safety by adding a continuous center turn lane. Construction is anticipated to start in 2026, four years earlier than planned.
- SH-44 from Star to SH-16: This project will add capacity by widening the road from three to five lanes between Mira Avenue and Moyle Ave. It includes resurfacing between Star Road and Mira Ave. Construction is anticipated to start in 2027, two years earlier than planned. Download a photo of the SH-44 and SH-16 intersection.
With these projects now included in the draft Idaho Transportation Investment Program (ITIP), the public will have the opportunity to give feedback on these projects and the department’s full list of planned projects from 2026-2032 during the annual comment period in July. Then the draft ITIP will be presented to the board for approval in September.
The board’s action today reflects continued investment targeting congestion and capacity in major corridors that were previously funded by TECM bonds as authorized by the Idaho Legislature. In Southwest Idaho, TECM funds have successfully extended SH-16 from I-84 to US-20/26 including the construction of five new interchanges, with the corridor set to open by 2027. These funds also allowed SH-55 to be widened to two lanes in each direction from Farmway Road to Middleton Road, with work set to be done in 2027.
These latest projects were identified because they are existing high-priority corridor needs that will improve traffic flow and increase safety.
The Idaho Transportation Department will shift traffic on Karcher Road (State Highway 55) Thursday night from the Middleton Road intersection through the Midway Road intersection as part of ongoing efforts to widen it to four lanes. Traffic will move to the newly paved temporary shoulder to allow crews to work on the existing lanes of the highway in the coming months.
Drivers can expect:
- Nighttime work from 10 p.m. to 5 a.m.
- SH-55 reduced to one lane with flaggers at night
- Permanent removal of the acceleration and deacceleration lanes at both intersections
Karcher Road will keep two lanes of traffic during the daytime with a center turn lane available at intersections. When complete, the highway will feature four lanes and dedicated turn lanes at intersections. The public can expect to see the closure of all acceleration and deacceleration lanes on Karcher Road by next year.
“We will need to shift traffic regularly to keep everyone moving while we widen the highway. Please be aware of your surroundings and drive with caution,” Project Manager Justin Wolf said. “Your safety and the safety of our workers depends on it.”
This work is part of the SH-55, Farmway Road to Middleton Road project, a larger effort to increase mobility and safety along the corridor in Canyon County. When construction is complete in 2027, improvements will include:
- Four lanes with dedicated left and right turn lanes at major intersections, including wider shoulders.
- A raised median from 10th Avenue to Middleton Road with right-in-right-out-left-in access at mid-mile intersections.
- A separated 10-foot bicycle and pedestrian pathway on the north and south sides of SH-55, and a pedestrian undercrossing east of 10th Avenue near Vallivue Middle School.
- Upgraded signal equipment at major intersections to allow for better timing between signals.
- Sound walls at Crestwood Estates, Fieldcrest Village and Lakeview Apartments.
- The Karcher View frontage road west of 10th Avenue on the north side of the highway.
To stay informed and get the latest information about the project and its traffic impacts visit itdprojects.idaho.gov/pages/55Farmway or text 55Farmway to 1-866-483-8422. For questions, contact the project team at (208) 477-1379. Maps and other details can also be found on the project website.
Starting tonight the contractor will return to Chinden Boulevard to address the limited sections from last year’s chipseal project that did not meet ITD standards. Repairs will protect the driving surface and extend the life of the roadway.
Between Glenwood Street and Eagle Road, the highway will receive a thin asphalt overlay resurfacing. From Eagle Road to Linder Road, pavement sealer will be sprayed on to the road to protect it, and lines will be freshly painted.
Work will be done at night from 7:30 p.m. to 5 a.m. to minimize impacts to travelers. One lane will be closed in each direction at night for up to six weeks. All lanes will be open during the day when crews are not on site.
Travelers should check 511.idaho.gov to know before they go.
The Idaho Transportation Department will close I-84 under the Karcher Interchange Tuesday and Wednesday nights to place girders on the overpass bridge. Detours will be in place.
Closures will run from 10 p.m. to 5 a.m. each night. On Tuesday night, westbound traffic will be affected, and on Wednesday night, eastbound traffic will be affected.
Motorists traveling westbound on I-84 Tuesday night will:
- Exit I-84 at the Northside Interchange (Exit 35).
- Travel north on Northside Blvd.
- Turn left on to Karcher Road.
- Travel west until you reaching the Karcher Interchange westbound on-ramp.
- Use the Karcher Interchange westbound on-ramp to merge back on to westbound I-84.
Motorists traveling eastbound on I-84 Wednesday night will:
- Exit I-84 using the Karcher Interchange eastbound off-ramp (Exit 33).
- Cross Karcher Road.
- Use the eastbound on-ramp to merge back onto I-84.
View the detour maps at ITDProjects.idaho.gov/pages/Karcher IC Maps
The girders were fabricated locally and will support the new westbound lane on Karcher Road over the interstate. ITD will host a Facebook live event during the girder placement on Tuesday, June 10. To tune in visit the ITD Facebook page.
Improvements on this project include:
- Adding a free running right hand turn at the westbound off-ramp
- Paving a third westbound lane on Karcher Road from the westbound off-ramp to Sundance Road
- Reinforcing the Karcher Interchange and Indian Creek bridges to support the new lane
- Updating signal equipment and adding a pedestrian flashing beacon at the eastbound on-ramp
- Building a separated mixed-use path on the north side of Karcher Road
These improvements will increase safety and traffic flow at the interchange. Construction is expected to finish in fall 2025.
Stay informed by signing up for email and text alerts regarding project updates. Text 84CORRIDOR to 1-866-483-8422 or visit itdprojects.idaho.gov/pages/karcheric. For questions, contact the project team at (208) 334-8002. Maps and other details can also be found on the project website.
